We know microgravity is terrible for us but we don't have data on 1/3 gravity. We might be fine. Or maybe we'd be fine if we took this drug, did some weight training, and added twenty minutes of centrifuge every day.
For the trip, there are several ways we could set up spin gravity.
For more on this "we don't really have the data for anything" problem, a humorously approachable read is "A City On Mars" [0]. Also the "nobody knows how laws would work" and other interesting complications.
For the trip, there are several ways we could set up spin gravity.